1. Field of the Invention
This application relates to the process of pressurizing and evacuating the gas contents of a container and, more particularly, to liquid filled containers.
2. Prior Art
Devices for carbonating beverages in the home have been known for some time. They provide the consumer with an inexpensive means of carbonating normally flat beverages, such as water, juices, etc., to make home-made soda.
Commonly, home carbonators employ a pressurized carbon dioxide (CO2) cartridge with a seal at one end that is punctured to release a gas into a container or bottle in order to carbonate the beverage within. The CO2 within the cartridge is stored at pressures up to approximately 850 psi, and thus the bottle for storing the liquid to be carbonated must be a fairly heavy, thick-walled apparatus. Such systems were and are commonly used to make seltzer water. However, such heavy pressure bottles are expensive and relatively awkward to handle.
For example, U.S. Pat. No. 4,395,940 to Child, et al. discloses an appliance for making an aerated beverage utilizing a source of carbon dioxide and a pressure regulating valve to limit the pressure within the bottle to a predetermined pressure limit, at which point the source CO2 gas is vented with a whistling sound. This appliance has several drawbacks, not the least of which is the wasteful venting of the source gas upon reaching the predetermined pressure. Additionally, the device is housed in a relatively cumbersome package, which precludes easy portability.
In U.S. Pat. No. 4,867,209 issued to Santoiemmo, a portable carbonating device is shown having a pressurizer with an internal regulator for attaching to the top of a liquid-filled bottle to dispense CO2 therein. The CO2 is supplied from a disposable cartridge, which is pierced by a needle to deliver gas through the regulator valve and into the bottle. The regulator valve is mounted within a housing which has internal threads for mating with the external threads of the bottle and also a series of external threads on the upper end for mating with a cartridge-enclosing cap. In an alternative embodiment, the device utilizes a tire needle valve for retaining the CO2 within the cartridge between uses. However, after introducing CO2 to a bottle containing a liquid, it is intended that the entire device remain on the bottle for the pressure above the liquid to be maintained until the liquid has absorbed the CO2. The device cannot be removed, for example, to pressurize a different bottle since that would release the pressure above the liquid, thus defeating the purpose of the device.
In addition to a device which carbonates otherwise flat beverages, a need exists for a simple device to re-pressurize carbonated beverages after they have been opened by the consumer. Currently, carbonated beverages are sold in a variety of containers, ranging from 10-ounce to bulk-size one-, two- and three-liter thin walled plastic bottles. For the consumer, the most cost-efficient size is the large economy bottle. However, unless the contents are consumed quickly, the quality of the carbonation is greatly reduced, as the CO2 gas above the liquid escapes every time the bottle cap is opened. The CO2 within the liquid then bubbles out due to the reduced CO2 vapor pressure above the surface of the liquid, causing the remaining beverage to go flat. Commonly, a portion of the remaining flat contents is thrown away. It would be desirable to be able to recharge these economy-size soda bottles with CO2 in order to maintain the carbonation of the beverage. A carbonation apparatus in this case would need to limit the pressure level within the plastic bottle to pressures on the order of 70 psi in order to ensure the plastic does not rupture.
A relatively recent device tried to tackle these problems. U.S. Pat. No. 5,329,975 issued to Heitel, disclosed an apparatus comprised of 2 components. A CO2 bicycle tire inflator and a bicycle tire Schrader valve hermetically sealed to a 2-liter bottle cap. This device addressed the heavy and awkward problem, the wasteful gas problem (to a degree), and the device removal problem. The device also used a regulated trigger to limit the pressure level within the plastic bottle to 70 psi. Not withstanding these advances, many flaws still exist with the device and its stated purpose.
The stated purpose of said device was “a simple device to re-pressurize carbonated beverages after they have been opened by the consumer”. However, this may not be achieved, simply, by re-injecting the bottle with CO2. When carbonated soda is made, commercially, the pre-carbonated beverage is fed into a large device that brings the pre-carbonated beverage to a specific temperature and pressure. At this temperature and pressure, pure CO2, surrounding the beverage, dissolves naturally into the beverage. The carbonated beverage is then injected into waiting bottles at ambient temperature and pressure, and is then capped. Incidentally, a small amount of ambient air creeps into the mostly CO2 gas pocket above the beverage before it is capped. Thus, the ambient conditions of an unopened bottle of soda contain mostly CO2 and some ambient N2 and O2 (disregarding trace gasses).
When the bottle of soda is opened and consumed (½ of the bottle consumed for illustration purposes) a lot of things happen. The CO2, in solution, begins to come out of solution under a different temperature and pressure. When the bottle is capped, a large amount of ambient air is locked in the bottle. Once capped, the remaining CO2, in solution, keeps releasing from solution until it creates an equilibrium with the new ambient gas. The remaining CO2, both released from solution and remaining in solution adjusts to the new temperature and pressure of the bottle. Also, the new gas and liquid within the capped bottle are not static. Large amounts of N2 and O2, in the new gas, continuously mix with the soda. Dissolved N2 seems to have a minimal effect on the carbonation and taste of a soda (shown through experimentation). However, dissolved O2 tends to make the beverage flat (shown through experimentation)—likely through dissolved O2 displacement of dissolved CO2 or a breakdown of the carbonic acid in solution.
At first blush, Heitel's apparatus seems to work. However, Heitel's apparatus contains no feature to evacuate the ambient gas in the opened bottle before it is pressurized with CO2. In Heitel's apparatus, ambient air is trapped and pressurized along with the CO2 allowing the pressurized ambient air to degrade the taste and consistency (or “fizz”) of the beverage. A priming function (combination of both pressurization and evacuation functions) is necessary to achieve the correct gas type in the bottle.
Along with the inability of Heitel's apparatus to evacuate the ambient gas from the bottle, it is also unable to discharge an over-pressurization of the bottle in a controlled manner. Pressure exceeding the original bottles unopened condition tends to over saturate the beverage with CO2. Over-saturation leads to larger bubble and, to use the vernacular, a mouth full of foam. It is paramount, that the original pressure level of the unopened bottle is duplicated in order to approximate the gas conditions of an unopened bottle.
A more subtle problem exists with Heitel's pressure regulating system in that it is not adjustable. Heitel's pressure regulating system can be factory set to automatically charge just under the safety threshold of 70 psi, a carbonating pressure of about 60 psi, or an equilibrium pressure of about 55 psi. However, it cannot adjust between these levels in the field. This is due to the type and tension of the spring inserted in the button. The automatic pressure level can only be adjusted through spring replacement. Spring replacement would probably have to be done at the factory. Furthermore, automatic pressure setting adjustments for altitude, ambient air pressure, ambient temperature and differing unopened bottle pressures (by brand and bottling company) cannot be adjusted for in the field.
Another problem with Heitel's apparatus is that the patent suggests injection of pure CO2. Stated previously, the gas and the soda are not in a static state after the cap is put on. The gas and the soda continue to mix with each other, unseen. When a half empty bottle is injected with pure CO2, a huge amount of pressurized CO2 is introduced (not present in the small space above the soda in an unopened bottle). This CO2 starts to mix with the soda at the wrong pressure and temperature. What you get is over-saturation of CO2 (similar to an over-pressure) and the drink becomes super fizzy when it hits the tongue. Again, you get a mouth full of foam. Thus, pure CO2 injection is probably not the answer to preserving the “fizz” in a previously opened bottle of soda. A mixture of gasses such as N2 and CO2 will work better to maintain the “fizz” at a level similar to an unopened bottle (shown through experimentation).
Finally, Heitel's apparatus does not have a gage to monitor the pressure of the gas in the bottle. Heitel does make reference to a gage but it is inoperable in his embodiment. A gage is also paramount. The goal is to achieve a gas pressure, as close to the ambient gas pressure, of an unopened bottle. A gage is necessary to achieve the correct pressure. A pressurization function and an evacuation function are necessary to achieve the correct pressure. Additionally and previously stated, a priming function (combination of both pressurization and evacuation functions) is also necessary to achieve the correct gas type in the bottle.
In a related field, wine also requires a device for the pressurization and evacuation of a gas in a wine bottle in order to approximate the unopened ambient conditions of a previous gas in said wine bottle. Devices similar to Heitel's invention are also in use in the wine industry. A device that is able to evacuate the wine bottle of ambient air, and replace it with a gas, such as Argon, would be beneficial. Also, a device, able to leave the near pure argon in the wine bottle at atmospheric pressure, would be beneficial. Such a device, would release overpressure, through its evacuation function. A fine wine, under pressure, is frowned upon in the wine community. A need may exist here.
U.S. Pat. No. 6,530,401 is a device, contemplated, for the low pressure, priming of wine or Champaign bottles using nitrogen. It uses an electronic charging head coupled to a stopper with a bottle securing device. The charging head is meant to be mounted to a bar or large heavy object for proper charging. The special stopper and the bottle securing device, necessarily, sit high above the bottle making it difficult to set the bottle vertically in a commercial refrigerator without hitting the shelf above. The device uses a special elastic disk that is circular and inefficient. When the stopper is removed from the charging head, the bottle loses at least 0.3-0.6 bar of pressure during the uncoupling. This is unacceptable for high pressure, precision priming, charging, and evacuating. A device is needed to achieve a gas pressure as close as possible to the ambient gas pressure of an unopened bottle. A device is needed that will obtain variances of 0.01-0.02 bar when a charging head is removed from a sealing device. Also, the special elastic disk, by design, is prone to “blow out” at higher pressures. The device illustrated in this patent is relatively complicated, heavy and inefficient and is therefore uneconomical for household use.
In summary, a need exists for an improved hand-held device for the pressurization and evacuation of a gas in a bottle in order to approximate the unopened ambient conditions of a previous gaseous state in said bottle.